We have seen Sefnit using the 3proxy service to proxy HTTP traffic to emulate a user browsing the Internet and clicking on advertisements.

Uses your PC for Litecoin mining

Some versions of this threat use your PC to mine Litecoins. Litecoin is a crypto currency similar to Bitcoins. Side effects may include slower computer performance, hardware degradation, and higher power consumption.

Additional information

This variant of Sefnit family is known to use SSH provided by PuTTY as its C&C communication channel. Outgoing SSH connections on port 443 to one of the following C&C servers is expected in some cases: